There's an innumerable amount of straps available on the market, all by an equally innumerable amount of companies. I highly suggest you go to a music store and test a lot of straps that are to your liking.

If you get a strap, try to get one with padding on the area where it will be hanging on your shoulder. I found this to be a LOT more comfortable but honestly, that's something you'll notice immediatly yourself.

Levy's makes the best Neoprene strap if you don't mind the super duper amount of stretch. Comfort Strapp is great if you string your bass high and don't mind not moving it. Also I believe I hipped Ben onto the Neotech so it's a fine alternative as well.

For my Vampyre I use a Levy's 3" leather strap. It's under the Hard Rock section and it's plain. Believe James Hetfield also uses it.